1. Field of the Invention
The present invention relates to a method of controlling a luminance of a light source and a display apparatus for performing the method. More particularly, the present invention relates to a method of controlling a luminance of a light source capable of enhancing display quality of an image having a pure color and a display apparatus for performing the method.
2. Description of the Related Art
Generally, a display apparatus includes a liquid crystal display (LCD) panel displaying an image using light transmittance of liquid crystals and a backlight assembly disposed under the LCD panel to provide light to the LCD panel. The LCD panel has an RGB structure. The RGB structure includes red, green and blue subpixels, and each of the red, green and blue subpixels typically has a rectangular shape.
Recently, a pentile RGBW structure including red, green, blue and white subpixels has been developed. The pentile RGBW structure offers the advantage of using fewer subpixels to achieve the same resolution as the RGB structure. Since the RGBW structure includes the white subpixel, the LCD panel having the RGBW structure has high transmittance. As a result, lower luminance is required of the backlight assembly and power consumption of the display apparatus may be decreased.
However, in the display apparatus having the pentile RGBW structure, a white subpixel in an area on which a pure color image is displayed is turned off and red, green and blue subpixels in the area are turned on for displaying the pure color image that is saturated with colors. Due to the white subpixel being turned off for pure color images, the luminance level is lower for pure color images in a display apparatus incorporating the pentile RGBW structure.